To prepare an integration composite of metal and plastic, a pore is firstly made on a surface of the metal, and then a plastic is injection molded on the surface of the metal. There are three commonly used methods of preparing pores on a surface of a metal. The first one is laser engraving, which uses a laser equipment, micro-pores are produced on a surface of a metal via laser ablation through this method. The second method is nano-hole etching, which is also known as nano-injection (PMH), that is, with an opening step of anodic oxidation, plus a step of T treatment, micro-pores are produced on a surface of a metal. The third one is metal etching, with this method, an ink is sprayed on a surface of a metal, and part of the ink on a protective area (where no etching is needed) is cured, and then the other part of the ink, which has not been cured, is removed, and then the metal is etched with an etching solution to produce micro-pores on the surface of the metal, and finally the cured ink is removed.
Although the first method may have a good effect, its processing efficiency may be low, its equipment investment may be large, the equipment may has a short life because of overloaded operations, and the cost may be large, thus it may be difficult to apply the first method into mass production. The second method may be only suitable for some metals, such as aluminum alloy, while it is not suitable for an anti-corrosion metal, such as stainless steel, magnesium alloy. The third method generally needs a screen plate to cover part of the metal which does not need to be cured, thus its technological requirements may be high, and its technique is complex, and it may have a high cost, and an etching depth is limited. What's more, a binding strength of a composite of metal and resin obtained via these methods may still need to be improved.